He engaged in real estate and banking in New York City and was appointed to various posts having to do with urban development.

[1] He engaged in real estate and banking in New York City and was appointed to various posts having to do with urban development.

[citation needed] On April 14, 1892, Maclay was appointed as member of the Rapid Transit Commission.

[citation needed] Maclay was a Director of Bowery Savings Bank and a trustee of the Northern Dispensary.

He was a trustee of the Madison Avenue Baptist Church and The Manhattan Club and was one of the incorporators of the New York Botanical Garden.